ᐅ Full-rafter insulation for roofs or insulation on concrete slabs

Created on: 28 Sep 2020 10:35
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exto1791
Hello everyone,

We are planning to build the ceiling on the upper floor as a concrete slab instead of a wooden structure – now the question is about the insulation for the upper floor/roof.

According to the energy-saving regulations, the roof no longer requires insulation; it is sufficient to insulate the concrete slab. The attic space will not be used as living space (city villa – 2 full floors) but only as utility space.

Since full rafter insulation is naturally much more expensive, the question arises whether insulation on the concrete slab is sufficient?
11ant4 Oct 2020 12:11
BackSteinGotik schrieb:

Is it worth adding additional insulation between the rafters if there is already ceiling insulation in the upper floor?
Yes, @Nordlys did exactly that – including a "balcony door" between the stair exit and the storage room.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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Nordlys
4 Oct 2020 16:52
What do you mean by worthwhile? It’s not worthwhile in terms of gas consumption. It is worthwhile to truly use the attic as a storage space and for hobbies. Our boat cushions, for example. Without insulation, the attic used to be damp up there; now it stays completely dry in winter. The model train can stand there now, and I can play with it. Paint no longer freezes, and so on. So, in the end, it is indeed worthwhile.
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exto1791
5 Oct 2020 07:34
Nordlys schrieb:

What do you mean by worthwhile? It’s not worth it in terms of gas savings. It’s worth it to actually use the attic as storage space and for hobbies. For example, our boat cushions used to get damp up there when it wasn’t insulated, but now in winter they stay completely dry. The model train can stay there now, and I can play with it. Paint doesn’t freeze anymore, etc. So in the end, it really is worth it.

We have a basement and a living area of 160m² (1,722 sq ft). We’re planning to have two children in the future, and in about 15 years, we’ll probably need some space up in the attic for a few boxes, Christmas decorations, etc.

Should I really insulate the roof for this? Honestly, wouldn’t insulation on the ceiling suffice?
11ant5 Oct 2020 11:58
exto1791 schrieb:

We need some space up in the attic for a few boxes, Christmas decorations, etc.
Do I really need to insulate the roof for this? Honestly, wouldn’t insulation on the ceiling be enough?

Let me put it this way: items meant for a flea market or recycling center don’t need to be kept cozy and warm, and insulation will definitely cost much more than a can of paint. If access is only via a pull-down ladder, you’ll naturally be more selective about what actually gets stored up there.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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Nordlys
5 Oct 2020 12:19
Everyone has their own preferences... for some, it’s worth it, for others it would just be throwing money away...
Golfi905 Oct 2020 13:48
I would say the 1000€ is well spent! We did the same.